net.openhft.chronicle.core.scoped

Class ScopedThreadLocal<T>

java.lang.Object

net.openhft.chronicle.core.scoped.ScopedThreadLocal<T>

All Implemented Interfaces:

ScopedResourcePool<T>

public class ScopedThreadLocal<T>
extends Object
implements ScopedResourcePool<T>

Bounded per-thread pool of ScopedResource instances.

Every thread owns its own stack of resources supplied by supplier. An instance is taken from the stack when get() is called and returned to it when the scope closes. If the stack is full the newest resource is discarded.

The stack is confined to a single thread and so is not synchronised. The resources themselves may not be thread-safe and must only be used by one thread at a time unless they implement their own safety rules.

Constructor Summary

Constructors

Constructor and Description
ScopedThreadLocal(@NotNull Supplier<T> supplier, @NotNull Consumer<T> onAcquire, int maxInstances) Creates a pool with an action run on every acquisition.
ScopedThreadLocal(@NotNull Supplier<T> supplier, @NotNull Consumer<T> onAcquire, int maxInstances, boolean useWeakReferences) Creates a pool with fine-grained control over resource retention.
ScopedThreadLocal(Supplier<T> supplier, int maxInstances) Creates a pool with the given supplier and capacity.

Method Summary

Modifier and Type	Method and Description
ScopedResource<T>	get() Obtains a scoped handle to a pooled instance.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ScopedThreadLocal

public ScopedThreadLocal(Supplier<T> supplier,
                         int maxInstances)

Creates a pool with the given supplier and capacity.

Parameters:

supplier - provides new instances when the stack is empty

maxInstances - maximum number of retained instances per thread

ScopedThreadLocal

public ScopedThreadLocal(@NotNull
                         @NotNull Supplier<T> supplier,
                         @NotNull
                         @NotNull Consumer<T> onAcquire,
                         int maxInstances)

Creates a pool with an action run on every acquisition.

Parameters:

supplier - provides new instances when the stack is empty

onAcquire - invoked each time an instance is retrieved from the pool

maxInstances - maximum number of retained instances per thread

ScopedThreadLocal

public ScopedThreadLocal(@NotNull
                         @NotNull Supplier<T> supplier,
                         @NotNull
                         @NotNull Consumer<T> onAcquire,
                         int maxInstances,
                         boolean useWeakReferences)

Creates a pool with fine-grained control over resource retention.

Parameters:

supplier - provides new instances when the stack is empty

onAcquire - invoked each time an instance is retrieved from the pool

maxInstances - maximum number of retained instances per thread

useWeakReferences - if true weak references allow garbage collection

Method Detail

get

public ScopedResource<T> get()

Obtains a scoped handle to a pooled instance.

Specified by:

get in interface ScopedResourcePool<T>

Returns:

the handle that must be closed to return the instance to this thread